A University of Florida engineer has crafted a nickel-sized imaging device that uses organic light-emitting diode technology similar to that found in laptop screens for night vision. The device is paper-thin, light and inexpensive, making it a possible add-on for cell phones.

Other applications could include night vision technology for car windshields, or even for standard glasses to use at night.
A paper detailing the infrared-to-vision device was published in a recent issue of Advanced Materials.

Standard night vision goggles use a photocathode to convert invisible infrared light photons into electrons. The electrons are accelerated under high voltage and driven into a phosphorous screen, producing greenish images of objects not visible to the eye in darkness. The process requires thousands of volts and a cathode ray tube-like vacuum tube made of thick glass. That is why the goggles tend to be bulky and heavy.

The new imaging device replaces the vacuum tube with several layers of organic semiconductor thin film materials. The structure is simple: It consists of a photodetector connected in series with an LED. When operating, infrared light photons are converted into electrons in the photodetector, and these photo-generated electrons are injected into the LED, generating visible light. The device – versions range from millimeter- to nickel-size -- currently uses glass, but it could be made with plastics, which would make it lightweight.

Conventional night vision goggles or scopes weigh 1 to 2 pounds, with price tags ranging from hundreds to thousands of dollars. Sized for cell phones, the  imaging devices weigh just a couple of ounces and would be inexpensive to manufacture because factories could use the same equipment used today to make laptop screens or flat-screen televisions.